1. Field of the Invention
The present invention relates to a communication apparatus and a communication process method. In particular, the present invention relates to a communication apparatus and a communication process method that control a plurality of antennas.
2. Description of Related Art
When communicating by a portable television reception apparatus, an antenna mounted to the portable television reception apparatus is used to receive wireless signals. In such a case, a user using the portable television reception apparatus often communicates while moving. In general, the antenna mounted to the portable television reception apparatus is usually a simple antenna. Therefore, the antenna mounted to the portable television reception apparatus has low tolerance to a change in the receive sensitivity. Thus, small fluctuation of the reception position may unable the reception. In order to solve such a problem, there is a method of mounting a plurality of antennas to the portable television reception apparatus and performing diversity reception. The diversity reception is that each of the antennas receives the same wireless signal and by synthesizing the received signal, the reception quality is improved.
However, in order to perform the diversity reception, it is necessary to prepare a tuner for each antenna, and the tuner has to process the wireless signal received by respective antenna. In general, the ratio of the electric power consumed by the tuner to the electric power consumed by a receiver for receiving the wireless signals is high. Therefore, if there are tuners provided for each of the antennas, a problem occurs in which the power consumption of the apparatus increases.
Thus, Japanese Unexamined Patent Application Publication No. 2007-43650 discloses a configuration to share one tuner by two antennas. The two antennas are alternatively switched, and if the reception quality of one antenna during communication is reduced, the tuner is switched to the other antenna to receive the wireless signals